Process of molding artificial stones with inscriptions



Cir

" pressions will be made Patented June 8%, 1923-5.

' UNITED stares JOSEPH EDWIN COCHRAN, OF MEMFHIS,

TENNESfiEE, ASFSIG'NOR 0F Olll'E-I-IALF TO ELLIS T. CRAWFORD, GE CHARLESTON, "WEST VIRGINIA.

PROCESS OF MOLDING ARTIFICIAL STONES WITH INSCRIPTIONS.

No Drawing.

In the molding of'artificial stone monuments having inscriptions, much difficulty is experienced in separatingthe stonesfrom the molds, or from the boards carrying the type characters, *ithout injury to the letters or characters cast in the stone, where the type cln-iracters from which tl'iese impressions are made are secured fast in the mold, or to the impression plate or board. On the other hand, if the type characters are not secured in fixed position within the mold, they are liable to be displaced when the plastic material which forms the stone is poured and rammed into the mold, and thus faulty imin the stone. In molding monuments having inscriptions, the type forming the inscriptions have to be changed for each stone, and it is important, therefore, to have some means of secur ng the type firmly in the mold so that they w1ll retain their places, during the pouring operation, and yet the type must be removable after the cast has been made in order that they may be replaced with type for forming another and different inscription.

In order to overcome these diliiculties attending the making of monuments with perfect inscriptions, I provide a smooth i1npression plate which forms the bottom of the mold, and to this plate I secure the type for molding the inscription by means of a water soluble cement. The cement is applied to the lower face of each type character, and the characters are then placed in the exact positions desired and the cement is allowed to set. I prefer to use a thin coating of liquid sodium silicate as a cementing material. This dries quickly and holds the type fast to the impression plate. After the cementing substance has become dry, I apply a thin coating of waterproofing material to the type characters, covering their edges so that the cementing material is protected from the direct action of the water in the plastic material when the latter is poured and rammed into the mold, which is the next operation. This coating is not entirely moisture-proof, but sufliciently'so to prevent the water in the plastic material from dissolving the cement which holds the type in place upon the impression board until the pouring operation is finished and the stone is partly set. After the stone has set sufficiently to be removed from the mold, it is taken out and the type will leave the i111- Appfioation filed. October 30, 1925; Serial No. 65,597.

pression board and adhere to the stone, the moisture from the plastic material compristhe stone having rmeated the n'ioistureresisting coating sufficiently to dissolve the cement which holds the type to the impression board.

As a watern'esisting material, I prefer to use a mixture of paratlin and carnauba wax in the proportions of about sixteen to one, by weight, and to this a small quantity of stearic acid is added. These ingredients are heated until they form a very thin liquid, which is applied to each type or impression character. After the stone, with the adherin type characters, has been removed from the mold, these characters are lightly tapped with a blunt instrument and fall out of the im aressions in the stone without injury to the latter.

The watei resisting compound being of a waxy nature, and in a thin film between the type characters and the mold, renders the characters easily removable from the stone. The stearic acid is added .to the other ingredients because, being in the nature of a grease, it reduces the adhesive properties of the compound and facilitates the removal of the characters from the stone.

lihat I claim'is:

1. The method of molding artificial stone monuments, with inscriptions, from plastic composition containing water which comprises atlixing the type characters for forming the inscription to an impression plate in the mold by water-soluble cementing material and permitting the material to dry. applying to the characters a coating of water-resisting material which will pre vent the water in the composition from immediately dissolving the cementing material but which will permit moisture to through and dissolve said cementing mate rial and loosen the type characters after a time, pouring the plastic composition into the mold asd allowing the same to set, re moving the finished stone, with the type characters adhering thereto, from the mold and then separating the typecharacters from the stone.

2. The method of molding artificial stone monuments, with inscriptions, from plastic composition containing water which comprises afiixing the type characters for form ing the inscription to an impression plate in the mold by water-soluble cementing mar terial and permitting the material to dry,

applying to the characters a thin coating of wax material which will prevent the water in the composition from immediately dissolving the cementing material but which will permit moisture to pass through and dissolve said cementing material and loosen the ype characters after a time, pouring the plastic composition into the mold and allowing the same to set, removing the finished stone, with the type characters adhering thereto, from the mold and then separating the type-characters from the stone.

3. The method of molding artificial stone monuments, with inscriptions, from plastic composition containing water which coniprises atlixing the type characters for forming the inscription to an impression plate in the mold by water-soluble cementing material and permitting the material to dry, applying to the characters a thin coating of waxy material, composed of paraflin, carnauha wax and stear'ic acid, which will prevent the Water in the composition from immediately dissolving the cementing material but which will permit moisture to pass through and dissolve said cementing material and loosen the type characters at ter a time, pouring the plastic composition into the mold and allowing the same to set, removing the finished stone, with the typemcharacters adhering thereto, from the mold and thenseparating the type-characters from the stone.

In testimony whereof I hereunto ttiilfi my signature.

JOSEPH ED'WIN GOGHRAN. 

